Liquid-measuring device



c. R. HARDY :LIQUID MEASURING DEVICE Filed Dec. 15, 1924 5 2 Sheets-Sheet 1 2 ATTORNEY.

Aug. 7, 1928. 1,680,103

c. R. HARDY LIQUID MEASURING DEVICE Filed Dec. 13, 1924 2 Sheets-Sheet 2 A TTORNEY.

- Patented Augr'i, 1928.

areas CHARLES E. HARDY, on Mount. VERNON, NEW YORK, AssIeNoE To THE surna- HEA'rEacoMPANY, OF NEW YORK, N. Y. Y I

LIQUID-MEASURING DEVICE.

Applicatioafiled December 13, 1924. Serial No. 755,804.

. My invention relatesto liquid measuring devices and has for. 1ts general ob ect the provislon of apparatus whlch will automatlcally add to a liquid entering a reservoir or other receptacle 1 apredetermined proportion of a seco'ndliquid, in order that a definitely proportioned mixture of the two liquids may always be available for withdrawal from the rcservoir,'regardless,ot-variations both as to time intervals between fillings and amounts added to the reservoir during individual filling operations. Other and further objectswill appear as the description proceeds.

lVhile ymy invention is 1 generally applicable to any case where itis desired to comtime two liquids in a reservoir in definite proportions,- it is particularly well adapted for usein adding scale-preventing or similar compounds, suchxas are described in the copending applicationiot' Julius .Alsberg, Serial #731,968 filed August 14tth, 192 1, to boiler feedwater, and especially so in locomotive practice Where the feed Water supply is carried in a tender, to which raw water is added and the treated feed water Withdrawn, intermittently, in varying quantities, and atvarying intervals. Moreover, this application of my invention illustrates its adaptability to reservoirs of various irregular shapes, and'in this connection the invention will be de::cribed as applied to 1000'- motive tender tanks of various forms.

a The construction and methodiot operation of my invention will be explained 'inthe following detailed descriptionof illustrative embodiments taken inconjunction with the accompanying drawings, in which:

Figure 1 is a longitudinal vertical section through a rectangular locomotive tender tankwith my invention installedtherein;

Figure 2 is a similar view with my invention installed in a tank having a varying cross section;

Figure 3is a detail of the apparatus as installed in the tank shown in Figure 1; and

Figure 1 is a view similar'to Figures 1 and "2, illustrating an installation in still another form of tank, 1

As shown in Figure 1, the tank 1, is of ordinary form andconstruction,is

provided with the usual outlet 2 at the bot-- tomthereoi, filling manhole 3, and swash plate 4. An auxiliaryreservoir or. tank 5, which contains the compound to be fed to which the main body of liquid in the tank 1, is

mounted adjacent the top of the tank 1 by any suitable means such as the U clamps {5,-and is provided with a fillin cap 7, having an aperture 8 therein which vents the tank 5' to the atmosphere. On or near the bottom of the main tank 1 is mounted the metering chamber 9 and a similar chamberscrewed orotherwise suitably secured the standpipe 13, which extends upwardly and ternnnates 1n the overflow outlet 14, opening preferably into the filling manhole 3 at the top otthe tank 1. The auxiliary reservoir 5 is connected with the chamber 9 by the pipe 15, which may be provided with the stop cock116, and in which is placed the check valve 17, permitting flow from the reservoir 5 into the chamber 9, and prevent ing return flow from the chamber 9 back into reservoir 5. The inter-communicating chambers, 9 and 10, are partlyfilled with mercury, indicated at 18, and where the cross sections of the chamber permit, splash plates 19 may be provided 1n order to minimize the surging due to motion of the loco- I motive tender in which the apparatus is inftalled.

The chamber 10 is closed at the top by a cover plate QO-through which extends one end of the pipe 21,'the other end of the lat ter terminating in a small orifice 22 closely adjacent the bottom of the tank 1, and providing free communication between chamber 10 and tank-1.

The operation of the apparatus is as follows: In Figure 1 the main tank l'is shown ervoir 5 will flow through pipe 15 into the metering. chamber 9 and will displace the opening 14 into the tank 1.

mercury therein by forcing it into the cham-v ber 10 until an equilibrium is established. This point. of equilibrium is established 'when the differences in the mercury level in V chambers 9 and 10 creates a static head ust into the standpipe 13 until the level theri'n is the same as that in the reservoir 5, which is at a point slightly below the highest point of pipe 13. y a

' When the tank 1 is filled it will be obvious that the water-rising therein will create a static head or pressure on the mercury in the chamber 10 through the communicating pipe 21 and aperture 22, and the pressure thus exerted on the surface of the mercury in the chan'rber 10 will vary directly as the height of the water level in the .tank 1. pressure in chamber 10 increases with the rising water level in the tank 1, the mercury in the chamber 10 will be gradually forced through the channel 11 into the metering chamber 9, and will displace some of the liquid with which the chamber has :been filled from the reservoir 5. The chambers 9 and 10 are so positioned that some mercury will be contained in each of the chambcrs 9 and 10 under all conditions; thatis, whether the tank 1 be. completely filled or entirely empty. If the tank 1 is empty, the

mercury level will, as heretofore explained, be as shown in Figure '1, with the mercury in the chamber 10 above the'level in cham her 9 a distance sufficient to create a head which will just balance the head of liquid in the reservoir 5. lVhen the tank 1 is full, the mercury will be as shown in Figure 3, with the level in the chambers 9 and 10 ap pi'o:\'i1'nate.ly the same due to the fact that the head acting upon the mercury in the chamber 10 and created by the contents of tank 1 is approximately equal to the head exerted on the mercury in the chamber 9 by the liquid in the reservoir 5.

hen the mercury in the metering chamber 9 rises, 'dueto the rising waterlevel in tank 1, theliquid in chamber 9 which is displaced by the mercury is prevented from returning to the reservoir 5 by the check valve 17, and is forced through the overflow As water is withdrawn from the tank 1, the falling wa ter level-therein relieves the pressure upon the chamber 10 and, as the head or pressure in chamber 9 created by the'substantially constant level of liquid in reservoir 5 remains at practically the same value, the mercury lev linchamber 9jwill reeede and additional liquid from the reservoir 5 will enter the top of the chamber 9 to replace that which lmS' been 1 forced through the overflow 14 into thetank 1; Upon an additional sup- As the ply of water being added to tank 1, the rising water level thereinwill repeat theaction' just described, themercury leyelin chamber 9 risingin direct proportion to the rise in levelin'tankl, and forcing additional liquid from the metering chamberthrough the" overflow let. It will be seen that thechambers 9 and 10 form, in effect, a reciprocating pump, the piston of which is formed by a confined fluid "column comprising in this case the body of mercury 18, which is actuated by .variations' in the static headof. the

water inthe tank 1, which varies according to the variation in the waterleve'l in the rises as the tankis'filled withiraw water,

there is produced the equivalent of a discharge stroke, in which the fluid 1n chamber:

9 is dischargedinto the maintankl; Thehorizontal cross'sect1onalareas of the chams here 9-and'10 are so proportioned thatequal changes in the mercury 'levelin the"-'twochambers will produce equal volumetric dis placements; It will be apparent fromithe' foregoing that wheneverwater is added'to the maintank 1, a quantity of the fluid from thechamber 9 is automatically forced into the main tank, and-the quantity of' liquid" transferred from the metering chamber 9 to the main tank will always be in proportion to the amount of water added to the main tank' 1. to be added to the water in the maintank is obtained by so proportioning the size of the meteringchamber 9' that a given fall or rise in the water level in the main tank willcause' the desired-quantity of'liquidfrom the reservoir 5 to'be drawn into the metering cham-' her 9, or discharged into the main tank, as

the case maybe V In-the illustrative embodiments, in which The desired proportion of liquid a boiler compound is added "to .raw feed" water, the amount added isivery-smal'l as compared to thequantity in-the main tank;

V For this reason mercury is used 'in. the cha n bore 9 and lO'as, due to the'high specific ravity of themercury,a variation in the wateijlever of the tank of severalr feet will produce a corresponding change'in the level of the mercury inf'thechambers of only a few inches, and consequently, a comparative ly small cubic displacement offluid-from the chamber 9 in response to thefadditi'on of large quantities ofv water to the tank 1; n1 1 cases where it is desired to add a larger quantity of va liquid, the horizontal sectionalarea of chambers 9- and 10 may be 'made r larger, or if the proportion is 'such as to warrant it, a liquid with a lower specific gravity: than that of mercury may be cm- 9 i ployed in order that the same variation in the water level 'in the tank 1 may produce a greater variation inthe liquid level in the chambers 9 and 1-0; whereby a'larger an'iount of the liquid to be added to the ma intank may be alternately drawn into and discharged from the metering chamber'9'.

In Figure 2 mv inventionis shown applied" to a tender tank of irregular section, in which the llOl'lZOIltitl cross sectlonal area in the lower pertion ot the tank is constant but mixture throughout the Working limits of the apparatus. e For the sake of clarity, the'apparatus as illustrated in Figure 1 isshown with the inlet to chamber 9, and outlet 13 therefrom. as separate conduits, but in actual prac time the simpler COIJSiDIUCi'AOII as shown in Figure 2 is employed wherein-the inlet pipe 15 connects at an intermediate point to the standpipe 18, whiclracts bothas inlet and discharge conduit for the chamber 9. Obviously the two forms oi piping arrangement are identical in function and operation.

As shown in Figure2 the water level in the main tank is indicated as being at the point' where the horizontal cross sectional area of the tank begins to progressivelydecrease as the heighto'l the'tank increases.

From the condition of an empty tank to the condition as shown in Figure 2, equal increments in the rise of water level in the tank representthe addition of equal volumes of water to the tank. Equal increments in the rise of the water level inthe main tank also produce equal increments in the change in level of the mercury in the chambers 10 and 9 and from the empty condition of the tank to tl e condition shown in Figure 2, the equal increments in change in the mercury level in cylinders 10 and 9' have displaced equal volumes of theliqnid from the chamber 9, because of the fact that themercury levels in chamber 10 have fallen andin 9" risen through cylindrical portions of the chambers wherein equal changes in level produce equal displacements in volume. 7 Up to this point the action of the apparatus, while the tank is being filled, isexactly the same as the action of the apparatus as shown in Figure 1". It'now, the tank, as shown in Figure 2, has additional water added thereto, equal in erements in the rise of the water level Will be produced by" progressively decreasing necessary that progressively smaller volumes of liquid be displaced from the metering chamber 9 by equal increments in the rise of the mercury level therein. This is accomplished by making this portion of the chamber 9 1n the former a truncated cone,

and the taper of the cone: is made so that the decrease in volumeper unit of height corresponds to the decrease in volume per 1)1'( l portional unit of height in the main tank '1. In this manner, the proportion between the liquid displaced from the chamber 9 and the quantity of water added to the main tank I is maintained as a constant ratio despite the variation in the sectional area ot the tank with respect to its height. In order to have the: rise in the mercury level in chamber 9 equal to the tall in the mercury level in chamber 10, it is obvious that the volume of the two chambers between the points of maxinnun and minimum mercury levels considered must be equal. Moreover, as inclicated in Figure 2, where chambers of varying sectional area are used, the variation in the sectional area must not only be equal but opposite from each otherwith respect to the height of the chambers in order that the mercury displaced from one chamber, say chamber 10, by a. given drop in the mercurv level, will cause an equal rise in the mercury tank acting on chambers 10, and the head caused by the liquid in the reservoir act-' ing on chamber 9. With this difference in-head known, the size and position of the chambers and the quantity of mercury used can be ascertained so that the mercury level in the respective will be as shown in Figure 2, with the mercury in bot-h chambers at the line of demarkationbetwcen the portions of constant and varying sectional areas, just as the water in the main tank is atthe line dividing the portions of constant and varying sectional area. i

In order for the apparatus to function with absolute accuracy, it is necessary that a constant head be maintained on the chainber 9. Unless this head is constant, and

consequently, the diiierence'in head between chambers any given position (for example, that shown in Figure 2) there will be avariation in the mercury level from that shown in Figure 2,

to be mixed with the water is used.

In other words,-the rising or falling mercury in the chambers would not pass from the constant area cylinder to the tapering portion of the chamber at the same instant that the water in the main tank passed fromthe constant area lower portion to the diminish- .ingarea upper portion of the tank.= Obviously, this would introduce an error in the proportioning of the two liquids being mixed, and, in actual: practice, a slight error of thls Y character-is incurred because oi the fact that the level in the reservoir 5 is not always constant, but gradually falls as the liquid This error, is, however, made'so smalhas to be negligible by making the reservoir 5 very shallow, and obtaining the necessary volume by making the horizontal cross sectional area as largelas may be necessary. hen the apparatus is used for the purpose described, in connection with locomotive tenders the reservoir 5 may be made not over 2 inches in depth, which means that the maximum variation in head is plus or minus 1 inch J from the mean-level in the reservoir. As the .total head involved is in the neighborhood ofsix feet in the ordinary tender, it

will be seen that this variation is so small that the head imposed by the liquid in reservoir 5 may be considered for all practical I purposes as being constant. In cases where, becauseof the large quantity of liquid used in the reservoir 5, it is impracticable to keep a substantially uniform level in'the reservoir 5, a second storage tank may be employed from which liquid is fed into the reservoir 5 in such a manner that the liquid level therein is always, a constant, and by this means a constant head may be vmaintained upon the metering chamber 9.

In Figure 4 my invention is shown as applied to a cylindical tender tank of the socalled Vanderbilt type. In this type ot tank.

'ferent volumes of water. In order to applymy invention to a .tank of very irregular section, such as this, it is only necessary to properly proportion the chambers 9 and 110, so that the rising or falling mercury level in them'will displace volumes which, through any given change in level, corresponds in a definite proportion to the volume V of water added or withdrawn from the main. tank; In practice, the simplest manner in whlch this may be accomplished, is to make the chambers 9 and 10' exact duplicates of the main tanlnexcept that they are on a smaller'scale. These chambers are then placed 1n inverted relatlonto each other in the same manner? as has been described in connection with Figure 2, so that the mercury.

level in each of the chambers is, at any given instant, at a point where the horizontal cross sectional areas of the chambersare equal,

In Figure 4- theapparatus is shown with the main tank filled, and the operation of the device, is, identical with that shown in. Figure 2. WVhile, as previously pointed out, the simplest manner in which to compensate for irregularities in thefmain tankvl is to make chambers 9 and 10 replicas thereof, it will be readily *seen that the same object may be attained by the use of reservoirs ot' other shapes, it the proportions of the reservoirs are computed so that the volume displaced by a given rise or tall in the mercur level will always be a definiteproportion of the displacement resulting trom the equivalent riseor fall of water level 1n the main tank. V

In order to prevent overflow from rcser; vo1rs5 or 5 directly into tank 1 through the outlet 14, it is, necessary fortheoutlet to be placed at a level slightly higher than the highest possible liquid. levelin the reservoir and this introduces a; slighterror which is rendered negligible by making the portion 7 oft-he outlet pipeabove the liquid level in the reservoir o't very'small diameter and consequently negligibly small volume.

As may readily be seen, if a portion of the contents of tank 1 be drawn 01f at thesame;

time that water is being added thereto, the change inwater level will not be a true measure of the quantity of water added to the tank, and for this reason the accuracy of the measuring apparatus is impaired.

It sometimes'happens in practice that feedwater is being withdrawn from atender during the time that it is being filled, but the rate at which feed water is withdrawn is so small as compared with the filling rate that the change in water level in the tender tank.

is for all practical purposes a true measure of the quantity of filling'water added, and no noticeable inaccuracy in the operation of the measuring device' is incurred. 5

lVhat I claim is: g V 1. In apparatusof the class described, the combination, with a main receptacle having a varying quantity of liquid therein; of an.

auxiliary receptacle containing a second liquid, a confined fluid column maintained under a pressureiabove atmospheric by an amount equal to theditference inhead between said liquids, and means whereby said column is actuated by variations-in the liquid level of said main receptacle totransfer said second liquid. from saidauxiliary. to

said main receptacle in'proportionfto the quantity of liquid added to said main receptacle. 2. In apparatus of the class described, a main-receptacle to which liquid is added and "from which liquid is withdrawn, an auxiliary.

receptacle containing a second liquid, and a fluid pumpv actuated by variations in the liquid level in said main receptacle, said pump having a metering chamber therein and operating to transfer a pre-determined proportion of said second liquid from said auxihary tank to said meter ng chamber as the liquid level 111 said mam tank falls, and

to transfer said second liquid in the same predetermined proportion from said meterchamber the horizontal sectional area of which is a constant pro-determined traction of the corresponding horizontal sectional area of said main tank, and means responsive to variations in the liquid in said main tank for automatically admitting said second liquid to said metering chamber and expelling it therefrom. V

4:. In apparatus of the class: described, a main receptacle having a varying liquid level therein, an auxiliary receptacle containing a second liquid, a pump having .a metering chamber the horizontal sectional area of which is a constant pre-determined fraction ,of the corresponding horizontal sectional area of said main tank, and means responsive to variations in the liquid in said main tank for, automatically admitting said second liquid to said metering chamber and expellingit therefroimin constant proportion to the quantity of liquid withdrawn from andad-dedto said main tank.

5. Inv apparatus of the class described, thecombination, with a main receptacle to which liquid is added and from which liquid is withdrawn; 0f an auxiliary receptacle containing a secondliquid, a metering chamber having a non-return inlet connected to said auxiliary receptacle andan out-let opening into said main receptacle, a motive liquid "in said chamber below said inlet. and said outlet, and means operating to produce a change in the level of said 'motive liquid in said metering chamber inconstant proportion to the change in liquid level in said 'main receptacle.

6. In apparatus of the class described, the" combination, .with' a main receptacle to which liquid isadded andfrom which liquid is withdrawn; of an auxiliary receptacle containing a second liquid, ametering chamber having a non-return inlet connected to said auxiliary receptacle, a; motive liquid in said metering chamber below said inlet, said motive liquid'having a specific gravity greater than that of said. first; named liquid, said main receptacle being in communication 7 with said meterlng chamber at a point above chamber having an inlet through which said second liquid is supplied, an outlet from sald metering chamber to said main receptacle,'and means operated by the Withdrawal of liquid from said main receptacle to admit to said metering chamber an additional quantity of said second liquid proportional to the quantity of liquid withdrawn from said main receptacle.

8. Apparatus of the class described, comprising, in combination, a main receptacle to which a liquid is admitted, an auxiliary receptacle containing a second liquid to be added to the liquid in said main receptacle, l

a metering chamber having an inlet through which said second liquid 15 supplied, a motive liquid in said. chamber, an outlet from said metering chamber tosaid main recepta'cle, and means operated by the addition of liquid to said main receptacle for causing said motive liquid to displace said second liquid from said chamber through said outlet to said main receptacle.

9. Apparatus of the class described, comprising, in combination, a main receptacle to which a liquid is admitted, an auxiliary receptacle containing a second liquid to be added to theliqnid in said main receptacle, a metering chamber having an inlet through which said second liquid is supplied,a motive liquid in said chamber, an outlet from said metering chamber to said main receptacle, and means operated by the addition of liquid to said main receptacle for causing said motive liquid to displace from said chamber through said outlet to said main receptacle a quantity of said second liquid proportionalto the quantity of liquid. added to said main receptacle.

10. A liquid measuring device comprising, in combinatioma metering chamber having inletand outlet means inth'e upper portion thereof, a second chamber, a connection between said chambers, a motive liquid in said chambers free to flow there between throughsaid connection, non-return means liquid and under a substantially constant static head, and means i'or'introducing anothcrliquid into said second chamber above said motive liquid and under a variable static head, whereby variations in the static head of said last named liquid, acting on said motive liquid, operates to pass said liquid to belhieasured throughsaid metering cliam'- her in pre deterhiinedamounts.

' 11, In apparatus of the" class described, a

ease-103 "auxiliary receptaletdone of sa"d'h"iinbers inaiii liquid containing receptacle, an auXiliary receptacle containingasecond liquid, pair ofchainbers the lowerportions of which are connected and containing a motive liquid free to flow throughsaid"connection,a nonreturn connection from said auxiliary re- "cepjtacle toone ofsaid chambers 'abovefthe -inotiveliquid therein, an outlet from said chamber to said main'r'ece'pt'acle', and a' con-" "hectidii fron'rthe second of saichchambers,

above the motiveliquid tli'erein'jopening into bottom thereof.

12. In apparatus of the 'class'described, a main liquid containing receptacle, an auXi1-' 'iary receptacle containing a second liquid and located substantially at the top of said main receptacle, a pair o'f'ch'ambers located substantially at the bottom of said main reabove the motive liquid therein, a

, Outlet 7 from said chamber tsaldillaliflcptacle,' and aconnection' i'rom' the second of'said chambers, above the 'motiveiliquid thereiii, 70:

opening into said 'mainlreceptac'l'eat apoint adjacent thebottom thereof. 1'5; Inapparatus of the class described, a

maiiii liquidcontaining" receptacle, an "aux- -iliar re ce atacle' containin a second'li uid 75 y l a: V i i a q pair of chambers with theirl'ower portions Connected, located below"said'auailiary re- I ceptacle and containing amotiveliquidfree to flow through said connectionysaid chambers being-constructed and arranged sothztt so the surface areas of said 'motive liquid in said "chambers are arcon'stant fraction of; the

correspondingsurface area or? the liquid in said main receptacle, a non-return connection from said auznliaryreceptacleto one 6 of said chambers above the motive liquid ccptacle, said chambersbeing connected at their lower portions and containing a motive liquid free toflow through said connection, a

'non return connection from said auxiliary receptacle to one of said chambers above the motiveliquid therein, an outlet from said chamber tosaid main receptacle, and a con nection from the second of said chambers,

above the motive liquid therein, opening into said main re'ceptacleat a point adjacent the bottom thereof.

' 13. In apparatus of the class described, a"

'mainliquid c'o'iit'aining receptacle, an auxil iary receptacle containing a second "llquid, a pair of chambers wlth their lower portions connected, located below said auxiliary ref motive liquid therein, an outletfromsaid chamber to said ma n receptacle, and a conceptaclefand containing a motive liquid free to flow through saidco'nnection, said-chambersbeingso proportioned that the ratio of any horizontal sectional area o'ffsaid chamhers to the corresponding horizontal sectional area of said 'main receptacle is a constant,

a non-returnconnection from saidauxiliary receptacle to-one of said chambers above the nection from the second of 'said'chambers, above the motive liquid therein, opening into said main receptacleat a point adjacent the bottom thereof.

' 14. in apparatus of the class described, a mainliquid containing receptacle, an auxiliary receptacle containing a second 'liquid, a pair of chambers with their lower portions 'connectedflocated below saidauxiliary receptacle and containing a motive liquid free to flow through said connection, said chambers being constructed and arranged so that the surface area of said motive liquid in one of said chambers is equal to the surface 'said chambersat all levels of said motive li'quld, a non-return connection from said area of said motive liquid in the other of therein, an outlet from said ch'a'lmber to'said main receptacle, and, a connection fromj the second of said chambers;above the" motive liquid therein, opening into said main re ccptacle at a point jai'djiacent the bottom thereof. i p i e 16. In apparatus of tlre classdescribed, a main liquid containing receptacle air *auxiliary receptacle'containing a s'econd li'quid, r

a pair of chambers with their lower portions connected, located below said imlXllfliLrY receptacle and containinga niotive'liquidfree to flow through. saidconnection,"'said ic'ham here being constructed and arranged so that W the surface area of said mot ve i l quid 1n *one of said chambers is equal to the surface area of said motive'li'quid 'in'theother ofsaid chambers at all levels ofsaid*motiveliquid,

' and said surface area being constant t'rac 106 tion of the corresponding s'urface area of the liquid 111 "saidmain receptacle, anonreturn connection from said auxiliary receptacle to one of said chambers abovethe motive liquid therein, an outlet from said cham 1 In 7 connected, located beloiv" said auxiliary re ie0 cepta'cle and containing acmotive liquid free to flow through said connection, tlie' corresponding' dimensions of saidchambersbeingt-hegsame, and one ofsaid chambers' being inverted 1 With i respect Y [tothe" other, non"-"- 12a return connection from "said auxiliary re- 3 ceptacle to one of sa d f 'chambersabov'c-the motive liquid therei 1r, an j'outlet i lirorn" "said chamber to said main receptacle, anda"connectio'n' from theseconu of said* chainbersg above the motiveliquid therein, opening into said main receptacle at a point adjacent the bottom thereof. I v

18, In apparatus of the class dcscribecba main liquid containing receptacle, an auxiliary receptacle containing a. second liquid,

f in

a pair of chambers with their lower portions connected, located below Sl1Cl auxiliary receptacle and containing a motive liquld free to fioW through said connection, the dimensionsot' each of said chambers being a constant traction of the corresponding dnnen- SlOIlS oi said main receptacle, a non-return 1 connection from said auxiliary receptacle to connected, located below said auxiliary receptacle and containing a motiveliquid free to flow through said connection, the dimen sions of said chambers being a constant frac" tion of the corresponding dimensions of said main receptacle and one of said chambers being inverted with respect to the other chamber, anon-return connection from said auxiliary receptacle to one of said chambers above the motive liquid therein, an outlet from said chamber to said main receptacle, and'a connection from the second of said chambers, above the motive liquid therein, opening into said main receptacle at a point adjacent the bottom thereof.

20. In apparatus of the class described, a main liquid containing receptacle, an auxiliary receptacle containing a second liquid,

ainetering chamber located below said auxiliary receptacle and containing a motive liquid, a conduit connecting said auxiliary receptacle With said metering chamber above the motive liquid therein, a non-return valve in said connection, a second conduit connected to said first named conduit at a point between said metering chamber and said non-return valve and opening into said main receptacle, said second conduit having a portion above the level of said auxiliary receptac-le, and means actuating said motive liquid to pass said second liquid through said metering chamber.

CHARLES R. HARDY. 

